Adaptive stabilization of a class of nonlinear systems withnonparametric uncertainty

We consider adaptive stabilization for a class of nonlinear second-order systems. Interpreting the system states as position and velocity, the system is assumed to have unknown, nonparametric position-dependent damping and stiffness coefficients. Lyapunov methods are used to prove global convergence of the adaptive controller. Furthermore, the controller is shown to be able to reject constant disturbances and to asymptotically track constant commands. For illustration, the controller is used to stabilize the van der Pol limit cycle, the Duffing oscillator with multiple equilibria, and several other examples     

Making Sense of Memory.

The current work explores how people make recognition and belief judgments in the presence of obvious repetition primes. In two experiments, subjects received a 200-ms prime ("cheetah"), either before or after reading a trivia question ("What is the fastest animal?") but always before being presented with the target answer ("cheetah"). Results showed that repetition priming decreased "old" claims (Recognition - Experiment 1), while it increased truth claims (Belief - Experiment 2). Furthermore, repetition prime placement affected recognition but not belief. Combined, these results suggest that dissociations in memory performance are a natural outcome of task and processing demands and reflect the dynamic, flexible nature of memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Functionalized Cluster‐Assembled Magnetic Nanostructures for Applications to high Integration‐Density Devices

This paper presents recent results on the preparation and characterization of original magnetic nanostructures from nanoclusters preformed in the gas phase. Magnetic binary‐clusters (i.e. Co‐Sm, Co‐Pt, Co‐Ag) with rather well controlled sizes, structures and compositions, are prepared in the gas phase using a combined laser vaporization‐rare gas condensation source and subsequently deposited at low energy (LECBD : Low Energy Cluster Beam Deposition) on various functionalized substrates to grow cluster‐assembled magnetic nanostructures exhibiting specific magnetic properties. Especially a high magnetic anisotropy and consequently a high magnetic blocking temperature compatible with future applications to high density memory devices and spin electronics are expected. In this context of applications, 2D‐organized arrays of functionalized binary‐cluster assembled dots are prepared by LECBD on FIB‐functionalized substrates (FIB: Focussed Ion Beam) with the ultimate objective to reach areal densities in the range of the Tbits/in².     

Robust H∞ stabilization via parametrized Lyapunovbounds

The parametrized Lyapunov bounding technique of Haddad and Bernstein (1991, 1993, 1995) is extended to include an H_∞ -disturbance attenuation constraint. The results presented in this paper provide a framework for designing fixed-order (i.e., full- and reduced-order) controllers that guarantee robust H₂ and H_∞ performance in the presence of structured constant real parameter variations in the state space model     

Robust controller synthesis via shifted parameter-dependentquadratic cost bounds

Parameterized Lyapunov bounds and shifted quadratic guaranteed cost bounds are merged to develop shifted parameter-dependent quadratic cost bounds for robust stability and robust performance. Robust fixed-order (i.e., full- and reduced-order) controllers are developed based on new shifted parameter-dependent bounding functions. A numerical example is presented to demonstrate the effectiveness of the proposed approach     

An Exploratory Examination of Student Attitudes Toward "Impaired" Peers in Clinical Psychology Training Programs.

Do psychology students view their training programs as doing enough to appropriately identify, accommodate, and possibly dismiss students who manifest significant impairment? This study reports the general findings of an exploratory survey distributed to clinical psychology graduate students. Overall, students viewed impairment as a highly sensitive and inadequately addressed issue. Students commonly reported frustration with and concern for impaired colleagues. A few respondents indicated that the terms impaired and problem student were insensitive and that greater attention needed to be given to "impaired" training contexts. Implications regarding formal standards for interpersonal functioning and programmatic supports for students are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fixed-structure discrete-time H 2 / H ∞ controller synthesis using the delta operator

This paper considers the fixed-structure, discrete-time mixed H 2 / H X controller synthesis problem in the delta operator (difference operator) framework. The differential operator and shift operator versions of the problem are reviewed for comparison, and necessary conditions are derived for all three formulations. A quasi-Newton/continuation algorithm is then used to obtain approximate solutions to these equations. Controllers are synthesized for two numerical examples, and the performance of the algorithm on the differential, difference and shift operator versions of the problems is compared.     

Relations between anxiety sensitivity, distress tolerance, and fear reactivity to bodily sensations to coping and conformity marijuana use motives among young adult marijuana users.

The present investigation examines anxiety sensitivity, distress tolerance, and fear reactivity to bodily sensations in relation to Coping and Conformity marijuana use motives among a sample of young adult marijuana users (n = 135; 46.7% women; Mage = 20.45, SD = 5.0). After controlling for current marijuana use frequency (past 30 days), daily cigarette smoking rate, average volume of alcohol used over the past year, negative affectivity, and other marijuana use motives, anxiety sensitivity was significantly and uniquely associated with Coping and Conformity motives for marijuana use. Distress tolerance evidenced significant and unique incremental relations to Coping motives, whereas fear reactivity to bodily sensations was unrelated to any marijuana use motive. These results provide novel information related to the role of emotional sensitivity and tolerance factors as they pertain to specific types of motives for marijuana use among young adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Estimation of human dose of staphylococcal enterotoxin A from a large outbreak of staphylococcal food poisoning involving chocolate milk

An outbreak of gastroenteritis in a school district in the United States was determined to be staphylococcal food poisoning due to 2% chocolate milk containing staphylococcal enterotoxin A (SEA). Twelve one-half pint (approx 0.28 l) cartons of the 2% chocolate milk from this outbreak were analyzed for the quantity of SEA present in the milk. The amount of SEA in the cartons varied from 94 to 184 ng with the average being 144 ng (mean = 139 +/- 45). The attack rate for vomiting among those who consumed more than one carton was greater (38.3%) than among those who consumed only one carton (31.5%) with the highest attack rate among those who consumed three or more cartons (44.4%).